Whitening cosmetic composition

ABSTRACT

A preparation for external use on skin which comprises an active ingredient exhibiting superior effects of preventing pigmentation or eliminating pigments formed in the skin, and has a high level of safety, and in particular, a cosmetic composition exhibiting superior so-called whitening effects, are provided. The whitening cosmetic composition comprises a tocopherol alkylglycine ester and/or a salt thereof.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit pursuant to 35 U.S.C. §119(e) ofU.S. Provisional Application No. 60/363,102 filed Mar. 12, 2002,pursuant to 35 U.S.C. §111(b).

TECHNICAL FIELD

The present invention relates to a preparation for external use on skinand to a whitening cosmetic composition, characterized by comprising atocopherol alkylglycine ester and/or a salt thereof, as an activeingredient, exhibiting effects of preventing pigmentation or eliminatingformed pigments in the skin.

BACKGROUND ART

Heretofore, many preparations for external use on skin have beenproposed and have been employed, in order to reduce pigmentation of theskin, such as spots and freckles due to exposure to UV rays, ordarkening observed after wounds or burns heal or observed after healingsurgical operation wounds.

For example, polyphenols are widely known as reducing decolorationeffects of melanin pigments. In particular, hydroquinone is widelyemployed in the field of clinical medicine in USA. However, hydroquinoneis pointed out as being strongly irritating on the skin, and for thisreason, it is difficult to employ it as a preparation for external useon skin, having a satisfactory level of safety.

In addition, vitamin C or derivatives thereof such as ascorbyl2-phosphate or ascorbyl 2-glucoside have been widely employed aspigmentation preventive agents in cosmetic compositions. However,according to our knowledge, the effects of preventing pigmentation ofthe ascorbic acids described above are weak, and they cannot be believedto be effective in view of many aspects. Furthermore, they exhibitsuperior effects of preventing pigmentation, but the effects of reducingdeposition of the formed pigments may or may not be sufficient.

Tocopherols, also known as vitamin E (such as α-tocopherol,β-tocopherol, γ-tocopherol, and δ-tocopherol), and derivatives thereofsuch as tocopherol acetate and tocopherol nicotinate, are known toexhibit effects such as antioxidation effects, effects of stabilizingvital membranes, immune activating effects, and effects of acceleratingblood circulation, and have heretofore been added to medicines,cosmetics, and the like; however, there has been no reference to theireffects of preventing pigmentation or eliminating formed pigments. Asfor tocopherols, there is an example of their effect as a remedy forpigmentation by their oral administration (K. Werininghaus et al., ArchDermatol, 130, 1257, 1994). In addition, there are examples of effectsof a specific derivative, tocopherol ferulic acid ester, in inhibitingpigmentation of cultured cells (M. Ichihashi et al., Anticancer Res.,19, 3769, 1999, and the like). However, effects of preventingpigmentation or eliminating formed pigments by dermal application oftocopherols have not been reported.

In addition, in order to avoid difficulty in view of formulation of theoil-soluble tocopherol derivatives described above, water-solubletocopherol phosphates, amino acid esters, or alkylaminocarbonates havebeen proposed.

DISCLOSURE OF INVENTION

Considering these circumstances, an object of the present invention isto provide a preparation for external use on skin having a high level ofsafety and comprising an active ingredient exhibiting superior effectsof preventing skin pigmentation or eliminating formed pigments in theskin, and in particular, to provide a cosmetic composition exhibitingsuperior so-called “whitening effects”.

As a result of diligent research in order to achieve this object, thepresent inventors discovered that tocopherol alkylglycine esters andsalts thereof exhibit strong effects of preventing skin pigmentation andeliminating formed pigments in the skin, thus completing the presentinvention.

That is, the present invention relates to the features described below.

[1] A whitening cosmetic composition characterized by comprising atocopherol alkylglycine ester and/or a salt thereof.

[2] The whitening cosmetic composition according to [1] described above,wherein the tocopherol alkylglycine ester is a compound represented byformula (1) described below:

-   -   wherein R₁ and R₂ represent the same or different lower alkyl        group or a hydrogen atom; and R₃, R₄, and R₅ represent a        hydrogen atom or a methyl group; with the proviso that R₁ and R₂        do not represent a hydrogen atom at the same time.

[3] The whitening cosmetic composition according to [1] or [2] describedabove, wherein the tocopherol alkylglycine ester is at least onecompound selected from an α-tocopherol alkylglycine ester, aγ-tocopherol alkylglycine ester, and a δ-tocopherol alkylglycine ester.

[4] The whitening cosmetic composition according to [1] described above,wherein the tocopherol alkylglycine ester is an α-tocopherolalkylglycine ester.

[5] The whitening cosmetic composition according to [4] described above,characterized in that the α-tocopherol alkylglycine ester is adl-α-tocopherol alkylglycine ester.

[6] The whitening cosmetic composition according to [4] described above,characterized in that the α-tocopherol alkylglycine ester is ad-α-tocopherol alkylglycine ester.

[7] The whitening cosmetic composition according to [1] or [2] describedabove, characterized in that the tocopherol alkylglycine ester is aγ-tocopherol alkylglycine ester.

[8] The whitening cosmetic composition according to [7] described above,characterized in that the γ-tocopherol alkylglycine ester is ad-γ-tocopherol alkylglycine ester.

[9] The whitening cosmetic composition according to [1] or [2] describedabove, characterized in that the tocopherol alkylglycine ester is aγ-tocopherol alkylglycine ester.

[10] The whitening cosmetic composition according to [9] describedabove, characterized in that the δ-tocopherol alkylglycine ester is ad-δ-tocopherol alkylglycine ester.

[11] The whitening cosmetic composition according to any one of [1] to[10] described above, characterized in that the tocopherol alkylglycineester is tocopherol dimethylglycine ester.

[12] The whitening cosmetic composition according to any one of [1] to[11] described above, characterized in that the salt of a tocopherolalkylglycine ester is a salt of an organic acid or an inorganic acid.

[13] The whitening cosmetic composition according to [12] describedabove, wherein the salt of a tocopherol alkylglycine ester ishydrochloride.

[14] The whitening cosmetic composition according to any one of [1] to[13] described above, wherein an added amount of the tocopherolalkylglycine ester and/or the salt thereof ranges from 0.1 to 10% bymass.

[15] A method for preventing or eliminating pigmentation of the skin,wherein a tocopherol alkylglycine ester and/or a salt thereof isemployed.

[16] Use of a tocopherol alkylglycine ester and/or a salt thereof forpreventing or eliminating pigmentation of the skin.

[17] Use of a tocopherol alkylglycine ester and/or a salt thereof forpreparation of a pharmaceutical agent for use in preventing oreliminating pigmentation of the skin.

BEST MODE FOR CARRYING OUT THE INVENTION

First, a tocopherol alkylglycine ester and a salt thereof which are theingredients employed in the present invention are described.

A tocopherol alkylglycine ester employed in the present invention isemployed as an active ingredient having effects of preventingpigmentation or eliminating formed pigments in the skin, and is acompound represented by, for example, a formula (1) described below:

-   -   wherein R₁ and R₂ represent the same or different lower alkyl        group or a hydrogen atom; and R₃, R₄, and R₅ represent a        hydrogen atom or a methyl group; with the proviso that R₁ and R₂        do not represent a hydrogen atom at the same time.

The term “lower alkyl group” described in the definition of R₁ and R₂means a straight-chain or branched alkyl group having 1 to 6 carbonatoms. As examples thereof, mention may be made of methyl, ethyl,n-propyl, n-butyl, isopropyl, isobutyl, 1-methylpropyl, tert-butyl,n-pentyl, 1-ethylpropyl, isoamyl, n-hexyl, and the like. The mostpreferable group among these is a methyl group.

As a salt of the compound of the present invention, salts are notparticularly restricted, so Long as they are salts of an organic acid oran inorganic acid. As preferable examples thereof, mention may be madeof a hydrohalogenic acid salt, an organic acid salt, and the like. Amongthese, hydrochloride is preferable since it is advantageous in that thesolubility in water increases and handling is facilitated due to itspowdered form.

The tocopherol derivatives represented by the formula (1) describedabove have an asymmetric carbon at the 2-position of the chroman ring.For this reason, there are stereomers such as d-form, l-form, anddl-form. It should be understood that the present invention includes allthe isomers described above.

The compounds of the present invention may be produced by conventionalproduction methods, and an example thereof is described in thefollowing.

The compounds can be easily produced by performing an esterificationreaction between a tocopherol represented by the formula (2) describedbelow:

-   -   wherein R₃, R₄, and R₅ represent a hydrogen atom or a methyl        group,        and any one of an alkylglycine represented by the formula (3)        described below:    -   wherein R₁ and R₂ represent an identical or different lower        alkyl group or a hydrogen atom; with the proviso that R₁ and R₂        do not represent a hydrogen atom at the same time, a reactive        acid derivative thereof, and a hydrohalogenic acid salt thereof,        in a conventional manner.

In the case of directly performing the esterification using a freealkylglycine, usually, the reaction is preferably performed in thepresence of an active esterification reagent such asdicyclohexylcarbodiimide or N,N-disuccinimide oxalate. The solvent inthe reaction is most preferably pyridine.

In addition, in a reaction with a reactive acid derivative, a reactionemploying an acyl halide, and in particular, an acyl chloride ispreferable.

In the case of producing a salt of a tocopherol alkylglycine ester, thehydrohalogenic acid salt may be produced by once producing an esterform, and subsequently adding an acid thereto according to aconventional method, thus forming a salt, or alternatively, may beproduced by previously employing a salt of an alkylglycine as a startingmaterial.

The present invention relates to a whitening cosmetic compositioncomprising a tocopherol alkylglycine ester and a salt thereof.

The whitening cosmetic composition can be produced by adding 0.1 to 10%by mass and preferably 0.5 to 2% by mass of a tocopherol alkylglycineester and/or a salt thereof to an alcohol such as ethanol or propyleneglycol; preservatives such as methyl parahydroxybenzoate, ethylparahydroxybenzoate, butyl parahydroxybenzoate, or propylparahydroxybenzoate; purified water; and the like.

Examples of whitening cosmetic compositions include, for example, skinmilk, skin cream, foundation cream, cream for massaging, cleansingcream, lotion, pack, ointment, bath preparation, body soap, and thelike. The kinds thereof are not restricted, so long as they come intocontact with skin during use. They may be in the form of gel. Inaddition, the user may be any user irrespective of sex or age.

In addition, in the whitening cosmetic compositions of the presentinvention, ingredients other than those described above, which arecommonly employed in whitening cosmetic compositions, can be addedwithin a range which does not impair the effects of the presentinvention.

EXAMPLES

In the following, the present invention is described in detail byreferring to Examples. It should be understood that the presentinvention is not restricted to these Examples. In the Examples, theadded amount is based on % by mass.

Example of Synthesis

To a solution of 59.1 g of dicyclohexylcarbodiimide and 40.0 g ofN,N-dimethylglycine hydrochloride dissolved in 320 g of pyridine, asolution of 60.0 g of dl-α-tocopherol dissolved in 240 g of pyridine wasadded. The mixture was allowed to react for 8 hours while stirring atroom temperature, and pyridine was distilled out. 2000 ml of water and1000 ml of ethyl acetate were added to the residue, and about 40 g ofsodium carbonate was added thereto to adjust the pH to between 7 and 8.The ethyl acetate phase was separated. Extraction from the water phasewas carried out three time using 200 ml of ethyl acetate each time. Theethyl acetate phase which was separated and the ethyl acetate phasesused for extraction were combined, and the ethyl acetate was distilledoff. Ethyl acetate was added to the residue, the mixture was dried overanhydrous sodium sulfate, and solid substances were filtered out. Theconcentration of dl-α-tocopherol dimethylglycine ester in the filtratewas adjusted to between 7 to 8%. 20% hydrochloric acid in dioxane wasadded thereto for neutralization in an amount such that the molar amountof the hydrochloric acid is 1.5 times of that of the dl-α-tocopheroldimethylglycine ester. Solid substance obtained was collected byfiltration, and recrystallized in methanol/acetone solvent to yield 49.2g of dl-α-tocopherol dimethylglycine ester hydrochloride.

Example 1

Lotion 1

Ingredients 1) to 4) were uniformly dispersed and dissolved so as toobtain the final concentrations described below, and subsequently theresulting mixture was added to ingredient 5) with stirring, thusproducing Lotion 1. 1) dl-α-tocopherol dimethylglycine ester 2.00hydrochloride 2) Ethanol 5.00 3) Propylene glycol 5.00 4) Methylparahydroxybenzoate 0.20 5) Purified water 87.8Lotion 2

Ingredients 1) to 4) were uniformly dispersed and dissolved so as toobtain the final concentrations described below, and subsequently theresulting mixture was added to ingredient 5) with stirring, thusproducing Lotion 2. 1) d-α-tocopherol dimethylglycine ester 2.00hydrochloride 2) Ethanol 5.00 3) Propylene glycol 5.00 4) Methylparahydroxybenzoate 0.20 5) Purified water 87.8Lotion 3

Ingredients 1) to 4) were uniformly dispersed and dissolved so as toobtain the final concentrations described below, and subsequently theresulting mixture was added to ingredient 5) with stirring, thusproducing Lotion 3. 1) d-γ-tocopherol dimethylglycine ester 2.00hydrochloride 2) Ethanol 5.00 3) Propylene glycol 5.00 4) Methylparahydroxybenzoate 0.20 5) Purified water 87.8Lotion 4

Ingredients 1) to 4) were uniformly dispersed and dissolved so as toobtain the final concentrations described below, and subsequently theresulting mixture was added to ingredient 5) with stirring, thusproducing Lotion 4. 1) d-δ-tocopherol dimethylglycine ester 2.00hydrochloride 2) Ethanol 5.00 3) Propylene glycol 5.00 4) Methylparahydroxybenzoate 0.20 5) Purified water 87.8Lotion 5 (Comparative Control)

Ingredients 1) to 4) were uniformly dispersed and dissolved so as toobtain the final concentrations described below, and subsequently theresulting mixture was added to ingredient 5) with stirring, thusproducing Lotion 5. 1) Sodium ascorbyl 2-phosphate 2.00 2) Ethanol 5.003) Propylene glycol 5.00 4) Methyl parahydroxybenzoate 0.20 5) Purifiedwater 87.8Lotion 6 (Negative Control)

Ingredients 1) to 4) were uniformly dispersed and dissolved so as toobtain the final concentrations described below, and subsequently theresulting mixture was added to ingredient 5) with stirring, thusproducing Lotion 6. 1) Purified water 2.00 2) Ethanol 5.00 3) Propyleneglycol 5.00 4) Methyl parahydroxybenzoate 0.20 5) Purified water 87.8

All lotions described above were uniformly dissolved and exhibited goodstability over time.

Example 2

Lotion 7

Ingredients 1) to 4) were uniformly dispersed and dissolved so as toobtain the final concentrations described below, and subsequently theresulting mixture was added to ingredient 5) with stirring, thusproducing Lotion 7. 1) dl-α-tocopherol dimethylglycine ester 0.10hydrochloride 2) Ethanol 5.00 3) Propylene glycol 5.00 4) Methylparahydroxybenzoate 0.20 5) Purified water 89.7Lotion 8

Ingredients 1) to 4) were uniformly dispersed and dissolved so as toobtain the final concentrations described below, and subsequently theresulting mixture was added to ingredient 5) with stirring, thusproducing Lotion 8. 1) d-α-tocopherol dimethylglycine ester 0.10hydrochloride 2) Ethanol 5.00 3) Propylene glycol 5.00 4) Methylparahydroxybenzoate 0.20 5) Purified water 89.7Lotion 9

Ingredients 1) to 4) were uniformly dispersed and dissolved so as toobtain the final concentrations described below, and subsequently theresulting mixture was added to ingredient 5) with stirring, thusproducing Lotion 9. 1) d-γ-tocopherol dimethylglycine ester 0.10hydrochloride 2) Ethanol 5.00 3) Propylene glycol 5.00 4) Methylparahydroxybenzoate 0.20 5) Purified water 89.7Lotion 10

Ingredients 1) to 4) were uniformly dispersed and dissolved so as toobtain the final concentrations described below, and subsequently theresulting mixture was added to ingredient 5) with stirring, thusproducing Lotion 10. 1) d-δ-tocopherol dimethylglycine ester 0.10hydrochloride 2) Ethanol 5.00 3) Propylene glycol 5.00 4) Methylparahydroxybenzoate 0.20 5) Purified water 89.7Lotion 11 (Comparative Control)

Ingredients 1) to 4) were uniformly dispersed and dissolved so as toobtain the final concentrations described below, and subsequently theresulting mixture was added to ingredient 5) with stirring, thusproducing Lotion 11. 1) Sodium ascorbyl 2-phosphate 0.10 2) Ethanol 5.003) Propylene glycol 5.00 4) Methyl parahydroxybenzoate 0.20 5) Purifiedwater 89.7Lotion 12 (Negative Control)

Ingredients 1) to 4) were uniformly dispersed and dissolved so as toobtain the final concentrations described below, and subsequently theresulting mixture was added to ingredient 5) with stirring, thusproducing Lotion 12. 1) Purified water 0.10 2) Ethanol 5.00 3) Propyleneglycol 5.00 4) Methyl parahydroxybenzoate 0.20 5) Purified water 89.7

All lotions described above were uniformly dissolved and exhibited goodstability over time.

Example 3

Gel Composition 1

Ingredient 1) was uniformly dispersed in ingredient 2) so as to obtainthe final concentrations described below, and subsequently the resultingmixture was added to ingredient 3) with stirring, thus producing thedesired gel composition 1. 1) dl-α-tocopherol dimethylglycine ester 10  hydrochloride 2) Glycerol 20 3) Octyldodecyl myristate 70Gel Composition 2

Ingredient 1) was uniformly dispersed in ingredient 2) so as to obtainthe final concentrations described below, and subsequently the resultingmixture was added to ingredient 3) with stirring, thus producing thedesired gel composition 2. 1) d-α-tocopherol dimethylglycine ester 10  hydrochloride 2) Glycerol 20 3) Octyldodecyl myristate 70Gel Composition 3

Ingredient 1) was uniformly dispersed in ingredient 2) so as to obtainthe final concentrations described below, and subsequently the resultingmixture was added to ingredient 3) with stirring, thus producing thedesired gel composition 3. 1) d-γ-tocopherol dimethylglycine ester 10  hydrochloride 2) Glycerol 20 3) Octyldodecyl myristate 70Gel Composition 4

Ingredient 1) was uniformly dispersed in ingredient 2) so as to obtainthe final concentrations described below, and subsequently the resultingmixture was added to ingredient 3) with stirring, thus producing thedesired gel composition 4. 1) d-δ-tocopherol dimethylglycine ester 10  hydrochloride 2) Glycerol 20 3) Octyldodecyl myristate 70Gel Composition 5 (Comparative Control)

Ingredient 1) was uniformly dispersed in ingredient 2) so as to obtainthe final concentrations described below, and subsequently the resultingmixture was added to ingredient 3) with stirring, thus producing thedesired gel composition 5. 1) Sodium ascorbyl 2-phosphate 10 2) Glycerol20 3) Octyldodecyl myristate 70Gel Composition 6 (Negative Control)

Ingredient 1) was uniformly dispersed in ingredient 2) so as to obtainthe final concentrations described below, and subsequently the resultingmixture was added to ingredient 3) with stirring, thus producing thedesired gel composition 6. 1) Purified water 10 2) Glycerol 20 3)Octyldodecyl myristate 70

All gel compositions described above were uniformly dissolved, andexhibited good stability over time.

Example 4

Effects of Preventing Pigmentation

Hair on the entire surface of the back of each of 50 male Wiser Mapleguinea pigs (WM, SPF), 7 weeks old, was cut by means of electric hairclippers (0.05 mm blade), and was subsequently shaved by means of anelectric shaver, followed by covering with an adhesive stretch bandage(SILKYTEX, covered on the outside thereof with an aluminum foil) wherein6 holes of 1.5 cm×1.5 cm had been formed.

Each product of the Lotions 1 to 12 and the Gel compositions 1 to 6,prepared in Examples 1 to 3, in an amount of 0.05 ml, was successivelyapplied to 10 holes described above.

Four hours after the application, the application part was cleaned withabsorbent cotton which contained water, followed by drying.Subsequently, the animal was held by a retainer, followed by exposure ofUV rays having medium wavelength (UVB) with 300 mJ/cm² to each part froma distance of approximately 10 cm by means of a UV exposure apparatus(Shinano Co., Ltd., Toshiba FL40S/E30 model fluorescent lamp, equippedwith six SE lamps).

After the exposure, 0.05 ml of each of the same Lotions 1 to 12 and Gelcompositions 1 to 6 as described above was again applied to thecorresponding part.

The operation described above was repeated for 3 days. Fourteen daysafter the final exposure, the strength of pigmentation was evaluated byevaluation points according to the evaluation criteria described in thefollowing. Furthermore, the lightness of the skin at 5 spots in total,that is, the four corners and the center part of each of the applied andexposed parts was measured by means of a color-difference meter (MinoltaCo., Ltd., CR-20).

The effects of preventing pigmentation of each of the products weredetermined by the average value of the evaluation points (10 pieces ofdata per product) and the average value of the lightness (50 pieces ofdata per product). Evaluation criteria of pigmentation No pigmentationis observed evaluation point 0 Very slight pigmentation is evaluationpoint 1 observed Slight pigmentation is observed evaluation point 2 Fairdegree of pigmentation is evaluation point 3 observed Strongpigmentation is observed evaluation point 4

Results (average value) Evaluation Product point Lightness Lotion 1 0.863.0 Lotion 2 0.7 63.1 Lotion 3 0.6 62.8 Lotion 4 0.5 64.0 Lotion 5 2.161.8 Lotion 6 3.0 59.5 Lotion 7 2.0 61.7 Lotion 8 2.0 60.7 Lotion 9 1.562.0 Lotion 10 1.7 62.0 Lotion 11 3.0 59.9 Lotion 12 3.0 60.1 Gelcomposition 1 0.4 63.8 Gel composition 2 0.4 62.9 Gel composition 3 0.463.1 Gel composition 4 0.4 63.0 Gel composition 5 1.2 62.1 Gelcomposition 6 3.0 59.9

As is apparent from the results described above, in each of the Lotions1 to 4 and 7 to 10, and the Gel compositions 1 to 4, according to thepresent invention, superior effects of preventing pigmentation wereobserved.

Example 5

Effects of Eliminating Pigmentation

Hair on the entire surface of the back of each of 50 male Wiser Mapleguinea pigs (WM, SPF), 6 weeks old, was cut by means of electric hairclippers (0.05 mm blade), and was subsequently shaved by means of anelectric shaver, followed by covering with an adhesive stretch bandage(SILKYTEX, covered the outside thereof with an aluminum foil) wherein 6holes of 1.5 cm×1.5 cm had been formed. Subsequently, the animal washeld by a retainer, followed by exposure of UV rays having mediumwavelength (UVB) of 750 mJ/cm² to each part from a distance ofapproximately 10 cm by means of a UV exposure apparatus (Shinano Co.,Ltd., Toshiba FL40S/E30 model fluorescent lamp, equipped with six SElamps).

From 4 days after the exposure to 28 days, each product of the Lotions 1to 12 and the Gel compositions 1 to 6, prepared in Examples 1 to 3, inan amount of 0.05 ml, was successively applied to 10 holes describedabove, twice a day, that is, in the morning and in the evening.

Twenty-eight days after the exposure, the strength of pigmentation wasevaluated by evaluation points according to the same evaluation criteriaas described in the Example. The effects of preventing pigmentation wereevaluated by the average value obtained from the evaluation points (10data per product). Results (average value) Evaluation Product pointLotion 1 2.2 Lotion 2 2.2 Lotion 3 2.0 Lotion 4 2.0 Lotion 5 3.3 Lotion6 3.5 Lotion 7 3.0 Lotion 8 3.0 Lotion 9 3.0 Lotion 10 3.0 Lotion 11 3.5Lotion 12 3.8 Gel composition 1 2.2 Gel composition 2 2.1 Gelcomposition 3 2.0 Gel composition 4 1.9 Gel composition 5 2.9 Gelcomposition 6 3.5

As is apparent from the results described above, even in each of theLotions (1 to 4 and 7 to 10) and Gel compositions (1 to 4) according tothe present invention, superior effects of eliminating pigmentation wereobserved.

INDUSTRIAL APPLICABILITY

The whitening cosmetic compositions of the present invention have a highlevel of safety, and exhibit superior effects of preventing pigmentationor eliminating formed pigments in the skin. For these reasons, they areuseful as cosmetic compositions exhibiting superior so-called whiteningeffects.

1. A whitening cosmetic composition characterized by comprising atocopherol alkylglycine ester and/or a salt thereof.
 2. The whiteningcosmetic composition according to claim 1, wherein the tocopherolalkylglycine ester is a compound represented by a formula (1) describedbelow:

wherein R₁ and R₂ represent the same or different lower alkyl group or ahydrogen atom; and R₃, R₄, and R₅ represent a hydrogen atom or a methylgroup; with the proviso that R₁ and R₂ do not represent a hydrogen atomat the same time.
 3. The whitening cosmetic composition according toclaim 1, wherein the tocopherol alkylglycine ester is at least onecompound selected from an α-tocopherol alkylglycine ester, aγ-tocopherol alkylglycine ester, and a δ-tocopherol alkylglycine ester.4. The whitening cosmetic composition according to claim 1, wherein thetocopherol alkylglycine ester is an α-tocopherol alkylglycine ester. 5.The whitening cosmetic composition according to claim 4, characterizedin that the α-tocopherol alkylglycine ester is a dl-α-tocopherolalkylglycine ester.
 6. The whitening cosmetic composition according toclaim 4, characterized in that the α-tocopherol alkylglycine ester is ad-α-tocopherol alkylglycine ester.
 7. The whitening cosmetic compositionaccording to claim 1, characterized in that the tocopherol alkylglycineester is a γ-tocopherol alkylglycine ester.
 8. The whitening cosmeticcomposition according to claim 7, characterized in that the γ-tocopherolalkylglycine ester is a d-γ-tocopherol alkylglycine ester.
 9. Thewhitening cosmetic composition according to claim 1, characterized inthat the tocopherol alkylglycine ester is a δ-tocopherol alkylglycineester.
 10. The whitening cosmetic composition according to claim 9,characterized in that the δ-tocopherol alkylglycine ester is ad-δ-tocopherol alkylglycine ester.
 11. The whitening cosmeticcomposition according to claim 1, characterized in that the tocopherolalkylglycine ester is tocopherol dimethylglycine ester.
 12. Thewhitening cosmetic composition according to claim 1, characterized inthat the salt of a tocopherol alkylglycine ester is a salt of an organicacid or an inorganic acid.
 13. The whitening cosmetic compositionaccording to claim 12, wherein the salt of a tocopherol alkylglycineester is hydrochloride.
 14. The whitening cosmetic composition accordingto claim 1, wherein an added amount of the tocopherol alkylglycine esterand/or the salt thereof ranges from 0.1 to 10% by mass.
 15. A method forpreventing or eliminating pigmentation of the skin, wherein a tocopherolalkylglycine ester and/or a salt thereof is employed.
 16. Use of atocopherol alkylglycine ester and/or a salt thereof for preventing oreliminating pigmentation of the skin.
 17. Use of a tocopherolalkylglycine ester and/or a salt thereof for preparation of apharmaceutical agent for use in preventing or eliminating pigmentationof the skin.